Breaker scope is often treated as an accessory in diesel generator quotations, but it can decide whether the package connects cleanly to the project switchboard. The purchaser should know who selects the breaker frame, who sets the trip unit, and which protection documents are expected at handover.
What buyers should know first
A diesel generator breaker is not selected by output kVA alone. Voltage, current, short-circuit expectations, cable distance, installation method, and downstream protection coordination can all affect the breaker and panel scope. Yangzhou Tesla Power Equipment Co., Ltd. can quote generator package options, but final protection coordination should be reviewed by the project electrical engineer.
Breaker information to align
| Item | Why it matters | Information to include |
|---|---|---|
| Breaker rating | Must match generator output and project voltage. | Ampere rating, voltage, poles, and enclosure. |
| Trip settings | Incorrect settings can cause nuisance trips or poor protection. | Who provides settings and who approves them. |
| Fault study | Generator fault current differs from utility supply. | Available project fault calculations if any. |
| Cable interface | Terminal size and cable route affect installation. | Cable quantity, size range, gland plate, entry direction. |
| Test documents | Settings should not exist only as verbal comments. | Factory record, drawing, and commissioning checklist. |
In practice
Two generator sets with the same kVA can have different breaker requirements if one feeds a simple manual panel and the other feeds a coordinated factory switchboard. For export projects, the RFQ should also state whether the breaker is inside the generator-mounted panel, in a separate output cabinet, or excluded from the supplier scope.
Before locking the order, compare this topic with cable entry and breaker scope checks and short circuit and protection scope checks. For higher output comparison, see the 800kW 1000kVA Cummins diesel generator with ATS option.
Before requesting a quotation
- State the project voltage, frequency, phase, and maximum load current.
- Confirm breaker location and whether a trip unit is required.
- Ask who is responsible for protection coordination with downstream equipment.
- Send cable entry direction, cable sizes, and termination expectations.
- Request drawings showing breaker, terminals, controller, and output interface.
Questions purchasers often ask
Can the supplier set the breaker trip values?
The supplier can provide typical settings if enough project data is available, but the project electrical engineer should approve final coordination.
Is a generator breaker always included?
No. Some quotations include only the generator-mounted breaker, while others require a separate output panel or contractor-supplied switchgear.
Why does cable distance matter?
Cable distance can affect voltage drop, termination arrangement, and how protection coordination is reviewed.
What should be checked during commissioning?
Check breaker labeling, trip-unit settings, terminal tightness, phase sequence, insulation test records, and load-test behavior.
What mistake delays factory projects?
A common delay is discovering that the ordered breaker does not match the actual switchboard, cable, or protection-study requirement.